n = 46 provedO=

s(46)=7

The best packing known for 46 squares, side 7, Wolfram Bentz 2009
7
678
6.7827.782
nn+1

Proven

s(46)=7

  • optimal
  • exact

Citation record n-046

lowerBentz 2010, Electron. J. Combin. 17 (confirmed T-004, T-008)

Bounds

Best known packing

7

Found by
Wolfram Bentz 2009
Construction
hand
Source
[Kingbird]
Evidence
E-kingbird-upper-register
Verified upper bound

7

The reported value, verified here.

Evidence
E-basic-grid-upper
Reported lower bound

7

Proved by
Wolfram Bentz 2010
Kind
unavoidable points
Source
[Bentz 2010]
Evidence
E-bentz-2010-proof
Verified lower bound

7

The reported value, verified here.

Evidence
E-bentz-2010-proof, E-bentz46-theorem8-audit
Gap

0

Solved: the verified bounds meet.

Results in the register

Verification

upper: replayed here; lower: external proof (read here, defect recorded), audited here

—

Rigidity

not rigid, numerically checked, numerical multiprecision

Evidence: E-translation-escape-not-rigid

Scope

Square 39 of the retained witness (witness id 40) translates 1 along (0, 1) with the packing still valid, so the configuration admits a non-trivial feasible motion; 4 of its 46 squares do. Every constraint is exactly affine in the slide parameter, so the arithmetic carries no linearization error, but the coordinates are the witness's own finite-precision transcription: this settles the retained configuration, not the true optimum. Rigidity and optimality are independent, and this bears only on the former.

s(46) — solved

s(46)=7, proved by Wolfram Bentz (2010) in the same paper as s(13)=4.

The largest non-trivial proved case

At n=46 this is the largest n for which s(n) is known exactly other than through the two general families (perfect squares, and Nagamochi’s m2−1, m2−2). It belongs to the m2−3 family — 49−3=46 — for which exact values are known only at m=3,4,5,6,7: that is s(6)=3, s(13)=4, s(22)=5, s(33)=6, and this case. Corrected 2 October 2026: Nagamochi’s proof of both families is incomplete, his Lemma 1 being false; m2−1 is proved again by Karakuş (T-084) and m2−2 by chelokot’s Lean proof, replayed here (T-086; review). This register had recorded that proof as verified, its own error, logged as defect D-516.

Whether s(m2−3)=m holds for all m≥3 is an open conjecture. The evidence is five consecutive confirmations and no proof of the general statement — which, given that the analogous conjecture s(n2−n)=n survives small cases and then fails at n=17, is weaker evidence than it looks.

Verification Code

The programs behind this case’s verified bounds, by their evidence. The code column says how the code that ran stands to the code its producer used. VERIFIERS.md says what each program is and whose it is.

bound evidence run code programs
verified lower E-bentz-2010-proof a published proof no code no verification code
verified lower E-bentz46-theorem8-audit audited here independent V-sqpack-cover (first-party)
verified upper E-basic-grid-upper replayed here independent V-check-basic-bounds (first-party)